Booted up my PC today. Suddenly, after 5 minutes or so, the colors changed; everything's fuck ugly at the moment.
Settings in AMD VISION Engine Control Center were and are set to default; didn't change a thing.

Any ideas on this? I think it's within Windows. Replugging the video cable (GPU -> DVi to VGA converter -> Monitor) didn't help; resetting the monitor with the "Auto" button didn't do anything, resetting to factory settings also did nothing.